Messages in this thread | | | Date | Thu, 4 Apr 2013 16:22:16 -0400 | From | Eduardo Valentin <> | Subject | Re: [PATCHv2 1/3] thermal: introduce thermal_zone_get_zone_by_name helper function |
| |
On 04-04-2013 13:12, R, Durgadoss wrote: >> -----Original Message----- >> From: Eduardo Valentin [mailto:eduardo.valentin@ti.com] >> Sent: Thursday, April 04, 2013 3:43 AM >> To: Zhang, Rui >> Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; R, Durgadoss; >> Eduardo Valentin >> Subject: [PATCHv2 1/3] thermal: introduce >> thermal_zone_get_zone_by_name helper function >> >> This patch adds a helper function to get a reference of >> a thermal zone, based on the zone type name. >> >> It will perform a zone name lookup and return a reference >> to a thermal zone device that matches the name requested. >> In case the zone is not found or when several zones match >> same name or if the required parameters are invalid, it will return >> the corresponding error code (ERR_PTR). >> >> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com> >> --- >> drivers/thermal/thermal_sys.c | 34 >> ++++++++++++++++++++++++++++++++++ >> include/linux/thermal.h | 1 + >> 2 files changed, 35 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c >> index 5bd95d4..6e1da0a 100644 >> --- a/drivers/thermal/thermal_sys.c >> +++ b/drivers/thermal/thermal_sys.c >> @@ -1790,6 +1790,40 @@ void thermal_zone_device_unregister(struct >> thermal_zone_device *tz) >> } >> EXPORT_SYMBOL_GPL(thermal_zone_device_unregister); >> >> +/** >> + * thermal_zone_get_zone_by_name() - search for a zone and returns its >> ref >> + * @name: thermal zone name to fetch the temperature >> + * >> + * When only one zone is found with the passed name, returns a reference >> to it. >> + * >> + * Return: On success returns a reference to an unique thermal zone with >> + * matching name equals to @name, a ERR_PTR otherwise. >> + */ >> +struct thermal_zone_device *thermal_zone_get_zone_by_name(const >> char *name) >> +{ >> + struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL); >> + int found = 0; >> + >> + if (!name) >> + goto exit; >> + >> + mutex_lock(&thermal_list_lock); >> + list_for_each_entry(pos, &thermal_tz_list, node) >> + if (!strnicmp(name, pos->type, THERMAL_NAME_LENGTH)) { >> + found++; >> + ref = pos; >> + } >> + mutex_unlock(&thermal_list_lock); >> + >> + /* Success only when an unique zone is found */ >> + if (found != 1) >> + ref = ERR_PTR(-ENODEV); > > I think we should differentiate between the two cases: > 1. The zone does not exist at all > return NULL in this case > 2. There are multiple zones > return ERR_PTR(-EEXIST) in this case > > This way the calling function can figure out the exact reason > for failure.
I think the code documentation is already clear enough to say that this is for unique matches. But in case you want to differentiate these cases, I can resend it. Do you have a usage for this?
Besides, I would prefer to return ERR_PTR(-ENODEV) in the first case. The way it is in the original patch.
> > Thanks, > Durga > >> + >> +exit: >> + return ref; >> +} >> +EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name); >> + >> #ifdef CONFIG_NET >> static struct genl_family thermal_event_genl_family = { >> .id = GENL_ID_GENERATE, >> diff --git a/include/linux/thermal.h b/include/linux/thermal.h >> index 542a39c..0cf9eb5 100644 >> --- a/include/linux/thermal.h >> +++ b/include/linux/thermal.h >> @@ -237,6 +237,7 @@ void thermal_zone_device_update(struct >> thermal_zone_device *); >> struct thermal_cooling_device *thermal_cooling_device_register(char *, >> void *, >> const struct thermal_cooling_device_ops *); >> void thermal_cooling_device_unregister(struct thermal_cooling_device *); >> +struct thermal_zone_device *thermal_zone_get_zone_by_name(const >> char *name); >> >> int thermal_zone_trend_get(struct thermal_zone_device *, int); >> struct thermal_instance *thermal_instance_get(struct >> thermal_zone_device *, >> -- >> 1.7.7.1.488.ge8e1c > > >
| |